1. Field of the Invention
The present invention relates to a clutch actuating apparatus for a double clutch transmission, and more particularly, to a technology about an actuator that respectively engages/disengages two clutches of a double clutch transmission.
2. Description of Related Art
Double clutch transmissions, different from a single clutch transmission systems of the related art, are shifting systems equipped with two clutches and designed to form separate shifting lines while one clutch connects/disconnects the gears of the odd-numbered stages and the other clutch connects/disconnects the gears of the even-numbered stages, which facilitate driving, such as automatic transmission, and achieve larger improvement of fuel efficiency than manual transmissions.
Further, double clutch transmissions allow for smooth shifting, because disconnection of acceleration, chattering and difference when gears are engaged, which are generated in transmissions equipped with a single clutch, do not occur.
The double clutch transmissions are provided with a pre-select function that engages in advance a shift gear of a shift stage in a next desired shift line other than the present shift stage, and directly shift only by changing the operation of the two clutches.
That is, with shift stages of two different shift lines engaged, respectively, the transmission ratio outputted from the transmission is changed in accordance with which clutch of the two clutches is engaged.
As described above, a clutch actuating apparatus for engaging a clutch should engage a clutch while being mechanically moved by electric operation or hydraulic operation, such that sufficient force for engaging the clutch should be applied to an apply bearing and a function of compensating frictional wear is required to compensate increase of the operational stroke when the clutch is worn.
Further, the clutch actuating apparatus requires a self-opening function that allows the clutch to be automatically disengaged in order to ensure safety in an emergency, such as when power of a vehicle is cut, and is usually attached to the outer side of a transmission case; therefore, it is required to be mounted in a small size in order not to protrude a lot out of the transmission case or occupy a large volume.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.